A anode rotation type X-ray tube to increase the allowable load by moving the electron impact surface is very widely used in X-ray imaging apparatuses, such as an X-ray apparatus or an X-ray CT apparatus. As the anode rotation type X-ray tube, there are two types of a three-phase anode rotation mechanism used when high speed is required for starting and a two-phase anode rotation mechanism that is simple and inexpensive. The two-phase anode rotation mechanism is formed using two stator coils, and rotates a rotor coil by supplying the AC voltages, which are shifted in phase by 90° from each other, to the respective stator coils.
As AC voltage supply means, there is a circuit configured to include an inverter circuit section, in which two arm circuits each of which has two semiconductor switches connected in series are connected in parallel to each other, and a capacitor for shifting the phase by 90°, which is connected to one output side of the inverter circuit section. However, since a capacitor is used, it is difficult to accurately control the phase due to the influence of load change of the output destination, ambient temperature, or the like. On the other hand, as disclosed in PTL 1, there is a method of supplying the AC voltage to the two-phase anode rotation mechanism using an inverter circuit formed by connecting three arm circuits, each of which is formed by connecting two semiconductor switches in series, in parallel to each other. In this method, since it is not necessary to use a capacitor for the output of the inverter circuit section, it is possible to accurately control the phase.